This is about travel to the US for Thai nationals and what is required. Thai citizens who wish to travel to the US basically need a valid Thai passport. This and a US visa from Thailand. If one wishes to stay in the United States permanently. Then an immigrant visa will be needed. For those who are staying in the US to study, leisure or business purposes. The non-immigrant visa is suitable for you.
You can apply for the non-immigrant visa either in the US Embassy in Bangkok or the US Consulate in Chiang Mai. Immigrant visas and other K visas for spouses (K3 Spouse Visa) and fiancées (K1 Fiancee Visa) can only be processed through the US Embassy in Bangkok. Each type of visa has different requirements. If the applicant has a criminal history If there are any prior problems with US Immigration or carries a contagious disease may hinder the possibility of eligibility to obtain a US Visa from Thailand.
If a person wants to travel to the US for business purposes. Then one might need a B1 visa. B1 visas are available for Thai nationals who wish to travel to the US for business related concerns. This type of visa does not allow the holder to work in the US, and are usually valid for three months or less. An expedited visa process can be filed if you have important business to attend to.
For those who wish to travel to the US temporarily for leisure or for medical concerns. The US B2 Tourist Visa from Thailand will be needed. US Tourist Visas are non-immigrant visas which do not allow the holder to earn a salary in the US. To avail of this type of visa, one must be able to show proof of strong ties with Thailand such as stable employment, business and properties or dependants.